Mike, you might want to post this to xs-devel on XenServer.org. Some of the storage engineers there would be in s better position to diagnose. On Dec 19, 2013 5:10 PM, "Mike Tutkowski" <mike.tutkow...@solidfire.com> wrote:
> Hi, > > I have been experimenting with VM snapshots on XenServer and have noticed a > problem that I hope someone might be able to shed some light on. > > In a normal flow of taking a VM snapshot, reverting to it, then deleting > the VM snapshot, I have observed the following (which looks just fine): > > *SR:* > > uuid ( RO) : 2a061111-a8c8-11db-4a8b-f8d519f9ac3e > name-label ( RW): Test > name-description ( RW): iSCSI SR [10.10.8.108 > (iqn.2010-01.com.solidfire:3y8w.test.15; LUN 0: > 337938770000000ff47acc0100000000: 93.1 GB (SolidFir))] > host ( RO): XenServer-6.1-Tut-2 > type ( RO): lvmoiscsi > content-type ( RO): > > > - *Before VM snap:* > > > *Active:* > > uuid ( RO) : b4587018-9679-4fe7-ba72-5523cb988cec > name-label ( RW): i-2-21-VM-DATA > name-description ( RW): > sr-uuid ( RO): 2a061111-a8c8-11db-4a8b-f8d519f9ac3e > virtual-size ( RO): 16106127360 > sharable ( RO): false > read-only ( RO): false > > > - *After VM snap:* > > > *Base copy (contains the data of the previously active VDI):* > > uuid ( RO) : d167952d-deb4-4942-9ea8-c8b3777d885e > name-label ( RW): base copy > name-description ( RW): > sr-uuid ( RO): 2a061111-a8c8-11db-4a8b-f8d519f9ac3e > virtual-size ( RO): 16106127360 > sharable ( RO): false > read-only ( RO): true > > *Snapshot:* > > uuid ( RO) : 613dc799-cf69-445a-a2fe-611653e0b0c9 > name-label ( RW): i-2-21-VM-DATA > name-description ( RW): > sr-uuid ( RO): 2a061111-a8c8-11db-4a8b-f8d519f9ac3e > virtual-size ( RO): 16106127360 > sharable ( RO): false > read-only ( RO): false > > *Active (has the same UUID as the previously active VDI):* > > uuid ( RO) : b4587018-9679-4fe7-ba72-5523cb988cec > name-label ( RW): i-2-21-VM-DATA > name-description ( RW): > sr-uuid ( RO): 2a061111-a8c8-11db-4a8b-f8d519f9ac3e > virtual-size ( RO): 16106127360 > sharable ( RO): false > read-only ( RO): false > > > - *After revert to VM snap:* > > > *Base copy:* > > uuid ( RO) : d167952d-deb4-4942-9ea8-c8b3777d885e > name-label ( RW): base copy > name-description ( RW): > sr-uuid ( RO): 2a061111-a8c8-11db-4a8b-f8d519f9ac3e > virtual-size ( RO): 16106127360 > sharable ( RO): false > read-only ( RO): true > > *Snapshot (this VDI is un-touched):* > > uuid ( RO) : 613dc799-cf69-445a-a2fe-611653e0b0c9 > name-label ( RW): i-2-21-VM-DATA > name-description ( RW): > sr-uuid ( RO): 2a061111-a8c8-11db-4a8b-f8d519f9ac3e > virtual-size ( RO): 16106127360 > sharable ( RO): false > read-only ( RO): false > > *Active (this is a new VDI - the old active VDI was deleted):* > > uuid ( RO) : b21284fa-347a-459a-a8bf-0fcd7717a134 > name-label ( RW): i-2-21-VM-DATA > name-description ( RW): > sr-uuid ( RO): 2a061111-a8c8-11db-4a8b-f8d519f9ac3e > virtual-size ( RO): 16106127360 > sharable ( RO): false > read-only ( RO): false > > > - *After deleting VM snap:* > > > *Active (the snapshot is gone as is the base copy...the base copy was > rolled up into this VDI):* > > uuid ( RO) : b21284fa-347a-459a-a8bf-0fcd7717a134 > name-label ( RW): i-2-21-VM-DATA > name-description ( RW): > sr-uuid ( RO): 2a061111-a8c8-11db-4a8b-f8d519f9ac3e > virtual-size ( RO): 16106127360 > sharable ( RO): false > read-only ( RO): false > > Now, in my case, where I create an SR on the fly (in response to attaching > a CloudStack volume to a VM on XenServer for the first time) to house a > single VDI (which has guaranteed IOPS), I see the following erroneous > behavior when it comes to hypervisor snapshots: > > *SR:* > > uuid ( RO) : 70e06f08-2c9d-f9cf-4e64-2f064c11325a > name-label ( RW): /iqn.2010-01.com.solidfire:3y8w.test.19/0 > name-description ( RW): /iqn.2010-01.com.solidfire:3y8w.test.19/0 > host ( RO): XenServer-6.1-Tut-2 > type ( RO): lvmoiscsi > content-type ( RO): user > > > - *Before VM snap:* > > > *Active:* > > uuid ( RO) : 067572a8-fa4d-45b5-9365-2d7790a4b202 > name-label ( RW): i-2-21-VM-DATA > name-description ( RW): > sr-uuid ( RO): 70e06f08-2c9d-f9cf-4e64-2f064c11325a > virtual-size ( RO): 10737418240 > sharable ( RO): false > read-only ( RO): false > > > - *After VM snap (this appears just fine):* > > > *Base copy:* > > uuid ( RO) : 71d39b5b-6c90-4aa9-adbf-71b226652081 > name-label ( RW): base copy > name-description ( RW): > sr-uuid ( RO): 70e06f08-2c9d-f9cf-4e64-2f064c11325a > virtual-size ( RO): 10737418240 > sharable ( RO): false > read-only ( RO): true > > *Snapshot:* > > uuid ( RO) : afc66ec7-5493-4772-9318-6f72c9d971f8 > name-label ( RW): i-2-21-VM-DATA > name-description ( RW): > sr-uuid ( RO): 70e06f08-2c9d-f9cf-4e64-2f064c11325a > virtual-size ( RO): 10737418240 > sharable ( RO): false > read-only ( RO): false > > *Active:* > > uuid ( RO) : 067572a8-fa4d-45b5-9365-2d7790a4b202 > name-label ( RW): i-2-21-VM-DATA > name-description ( RW): > sr-uuid ( RO): 70e06f08-2c9d-f9cf-4e64-2f064c11325a > virtual-size ( RO): 10737418240 > sharable ( RO): false > read-only ( RO): false > > > - *After a failed revert to VM snap:* > > > uuid ( RO) : afc66ec7-5493-4772-9318-6f72c9d971f8 > name-label ( RW): i-2-21-VM-DATA > name-description ( RW): > sr-uuid ( RO): 70e06f08-2c9d-f9cf-4e64-2f064c11325a > virtual-size ( RO): 10737418240 > sharable ( RO): false > read-only ( RO): false > > Somehow the base copy and active VDI have both been deleted and the > snapshot VDI is the only remaining VDI. > > I would have expected the active VDI to be deleted and a new VDI (which is > initially empty) to take its place as the active VDI. The snapshot should > not be touched and the base copy should not be deleted. > > Does anyone have any insight as to why this may be happening? > > Thanks! > > -- > *Mike Tutkowski* > *Senior CloudStack Developer, SolidFire Inc.* > e: mike.tutkow...@solidfire.com > o: 303.746.7302 > Advancing the way the world uses the > cloud<http://solidfire.com/solution/overview/?video=play> > *™* >
